/* 
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined 
 * in FIPS PUB 180-1 Version 2.1a Copyright Paul Johnston 2000 - 2002. Other 
 * contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet Distributed under the 
 * BSD License See http://pajhome.org.uk/crypt/md5 for details. Configurable 
 * variables. You may need to tweak these to be compatible with the server-side, 
 * but the defaults work in most cases. 
 */  
var hexcase = 0; /* hex output format. 0 - lowercase; 1 - uppercase */  
var b64pad = ""; /* base-64 pad character. "=" for strict RFC compliance */  
var chrsz = 8; /* bits per input character. 8 - ASCII; 16 - Unicode */  
  
/* 
 * These are the functions you'll usually want to call They take string 
 * arguments and return either hex or base-64 encoded strings 
 */  
function hex_sha1(s) {  
    return binb2hex(core_sha1(str2binb(s), s.length * chrsz));  
}  
function b64_sha1(s) {  
    return binb2b64(core_sha1(str2binb(s), s.length * chrsz));  
}  
function str_sha1(s) {  
    return binb2str(core_sha1(str2binb(s), s.length * chrsz));  
}  
function hex_hmac_sha1(key, data) {  
    return binb2hex(core_hmac_sha1(key, data));  
}  
function b64_hmac_sha1(key, data) {  
    return binb2b64(core_hmac_sha1(key, data));  
}  
function str_hmac_sha1(key, data) {  
    return binb2str(core_hmac_sha1(key, data));  
}  
  
/* 
 * Perform a simple self-test to see if the VM is working 
 */  
function sha1_vm_test() {  
    return hex_sha1("abc") == "a9993e364706816aba3e25717850c26c9cd0d89d";  
}  
  
/* 
 * Calculate the SHA-1 of an array of big-endian words, and a bit length 
 */  
function core_sha1(x, len) {  
    /* append padding */  
    x[len >> 5] |= 0x80 << (24 - len % 32);  
    x[((len + 64 >> 9) << 4) + 15] = len;  
  
    var w = Array(80);  
    var a = 1732584193;  
    var b = -271733879;  
    var c = -1732584194;  
    var d = 271733878;  
    var e = -1009589776;  
  
    for ( var i = 0; i < x.length; i += 16) {  
        var olda = a;  
        var oldb = b;  
        var oldc = c;  
        var oldd = d;  
        var olde = e;  
  
        for ( var j = 0; j < 80; j++) {  
            if (j < 16)  
                w[j] = x[i + j];  
            else  
                w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);  
            var t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)),  
                    safe_add(safe_add(e, w[j]), sha1_kt(j)));  
            e = d;  
            d = c;  
            c = rol(b, 30);  
            b = a;  
            a = t;  
        }  
  
        a = safe_add(a, olda);  
        b = safe_add(b, oldb);  
        c = safe_add(c, oldc);  
        d = safe_add(d, oldd);  
        e = safe_add(e, olde);  
    }  
    return Array(a, b, c, d, e);  
  
}  
  
/* 
 * Perform the appropriate triplet combination function for the current 
 * iteration 
 */  
function sha1_ft(t, b, c, d) {  
    if (t < 20)  
        return (b & c) | ((~b) & d);  
    if (t < 40)  
        return b ^ c ^ d;  
    if (t < 60)  
        return (b & c) | (b & d) | (c & d);  
    return b ^ c ^ d;  
}  
  
/* 
 * Determine the appropriate additive constant for the current iteration 
 */  
function sha1_kt(t) {  
    return (t < 20) ? 1518500249 : (t < 40) ? 1859775393  
            : (t < 60) ? -1894007588 : -899497514;  
}  
  
/* 
 * Calculate the HMAC-SHA1 of a key and some data 
 */  
function core_hmac_sha1(key, data) {  
    var bkey = str2binb(key);  
    if (bkey.length > 16)  
        bkey = core_sha1(bkey, key.length * chrsz);  
  
    var ipad = Array(16), opad = Array(16);  
    for ( var i = 0; i < 16; i++) {  
        ipad[i] = bkey[i] ^ 0x36363636;  
        opad[i] = bkey[i] ^ 0x5C5C5C5C;  
    }  
  
    var hash = core_sha1(ipad.concat(str2binb(data)), 512 + data.length * chrsz);  
    return core_sha1(opad.concat(hash), 512 + 160);  
}  
  
/* 
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally to 
 * work around bugs in some JS interpreters. 
 */  
function safe_add(x, y) {  
    var lsw = (x & 0xFFFF) + (y & 0xFFFF);  
    var msw = (x >> 16) + (y >> 16) + (lsw >> 16);  
    return (msw << 16) | (lsw & 0xFFFF);  
}  
  
/* 
 * Bitwise rotate a 32-bit number to the left. 
 */  
function rol(num, cnt) {  
    return (num << cnt) | (num >>> (32 - cnt));  
}  
  
/* 
 * Convert an 8-bit or 16-bit string to an array of big-endian words In 8-bit 
 * function, characters >255 have their hi-byte silently ignored. 
 */  
function str2binb(str) {  
    var bin = Array();  
    var mask = (1 << chrsz) - 1;  
    for ( var i = 0; i < str.length * chrsz; i += chrsz)  
        bin[i >> 5] |= (str.charCodeAt(i / chrsz) & mask) << (32 - chrsz - i % 32);  
    return bin;  
}  
  
/* 
 * Convert an array of big-endian words to a string 
 */  
function binb2str(bin) {  
    var str = "";  
    var mask = (1 << chrsz) - 1;  
    for ( var i = 0; i < bin.length * 32; i += chrsz)  
        str += String.fromCharCode((bin[i >> 5] >>> (32 - chrsz - i % 32))  
                & mask);  
    return str;  
}  
  
/* 
 * Convert an array of big-endian words to a hex string. 
 */  
function binb2hex(binarray) {  
    var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";  
    var str = "";  
    for ( var i = 0; i < binarray.length * 4; i++) {  
        str += hex_tab  
                .charAt((binarray[i >> 2] >> ((3 - i % 4) * 8 + 4)) & 0xF)  
                + hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8)) & 0xF);  
    }  
    return str;  
}  
  
/* 
 * Convert an array of big-endian words to a base-64 string 
 */  
function binb2b64(binarray) {  
    var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";  
    var str = "";  
    for ( var i = 0; i < binarray.length * 4; i += 3) {  
        var triplet = (((binarray[i >> 2] >> 8 * (3 - i % 4)) & 0xFF) << 16)  
                | (((binarray[i + 1 >> 2] >> 8 * (3 - (i + 1) % 4)) & 0xFF) << 8)  
                | ((binarray[i + 2 >> 2] >> 8 * (3 - (i + 2) % 4)) & 0xFF);  
        for ( var j = 0; j < 4; j++) {  
            if (i * 8 + j * 6 > binarray.length * 32)  
                str += b64pad;  
            else  
                str += tab.charAt((triplet >> 6 * (3 - j)) & 0x3F);  
        }  
    }  
    return str;  
}